The claim that root canals cause cancer has persisted over the years despite a complete lack of scientific evidence. Root canals are common and safe restorative dental procedures that are not associated with the development of cancer in any part of the body, and researchers in 2013 actually found that people who have had root canals were less likely to develop cancers of the head or neck. Here’s a brief overview of where this claim came from and why root canals are perfectly safe.